Roller-type dressers for grinding wheels



March 21, 1961- H. E. BALSIGER ROLLER-TYPE DRESSERS FOR GRINDING WHEELS Filed Dec. 18, 1959 5 Sheets-Sheet 1 HAROLD E. EALSIGER ATTORNEY March '21, 1961 H. E. BALSIGER ROLLER-TYPE DRESSERS FOR GRINDING WHEELS Filed Dec. 18, 1959 5 Sheets-Sheet 2 INVENTOR HAROLD E.BALSIGER A6 5 fl ATTORNEY March 21, 1961 H. E. BALSIGER ROLLER-TYPE DRESSERS FOR GRINDING WHEELS Filed Dec. 18, 1959 5 Sheets-Sheet 3 INVENTOR' HAROLD E. BALE/GER ATTORNEY March 21, 1961 H. E. BALSIGER ROLLER-TYPE DRESSERS FOR GRINDING WHEELS Filed Dec. 18, 1959 INVENTOR HflROLD E. BALSIGER March 21, 1961 H. E. BALSIGER 2,975,782

ROLLER-TYPE DRESSERS FOR GRINDING WHEELS Filed Dec. 18, 1959 I IE' 5 Sheets-Sheet 5 .411? SUPPLY INVENTOR HARDLD E-BALSIGfP ATTORNEY ROLLER-TYPE DRESSERS FOR GRINDING WHEELS HaroldE. Balsiger, Waynesboro, Pa., assignor to Landis Tool Company, Waynesboro, Pa.

Filed eals, 1959, see. No. 860,476

7 Claims. 01. 125-11 This invention relates to grinding machines, particularly to the means for forming and renewingthe perative surfaces of a grinding wheel.

The particular type of 'forming device to which this invention relates is that known as a crusher. Conventional crushers are usually in the form of rollers which are fed radially relative to the abrasive Wheels to be crushed. Also, crush dressing is usually done with the crusher roller being driven and, in turn, driving the grinding wheel, or with the grinding 'Wheel drivenat slow speed with the crusher roller mounted for free rotation by the grinding wheel. Both of these are relatively slow processes. The crusher must always be supported in such a manner as to withstandthe force which must be applied to maintain the crusher roller in operative engagement with the grinding wheel.

It is, therefore, an object of the present invention to provide a crush dressing device in which the crushing operation is performed while'the grinding wheel is rotatedat grinding speed.

Another objectis to provide a crush dressing apparatus in which the crushing operation is performed by movement of the crusher axially of the grinding wheel.

Another object is to provide means=whereby the crushing action results from therelative high speed of the grinding wheel pressure more than from the'force'exerted Fig. 9 shows the position of the dressing rollers-'relative to the grinding Wheel when camllii is'in the position'shown in Fig. 6. g

Fig. 10 shows the position ofthedressing rollers relative to the grinding wheel when earn 110 is in the position shown in Fig.7. l

Figfll shows the position of the dressing rollers relative tothe grinding Wheel when cam 110 is in the position shown in Fig. 8. r

Fig. 12is an electric and hydraulic circuit.

Numeral 10 indicates a portion of the grinding wheel support of a grinding machine. Bracket 11 is mounted on portion 16. Support member 14 has a dove-tail portion 15 byjwhich it is attached for axial adjustment in-the lower end 16 or crusher carrying bracket 17. Bracket 17 is supported on shaft 13 rotatably mounted .in bracket 11. Bracket 17 is moved about shaft 18 by means of a Pi ton 162 andcylinder161 connected through piston. rod 25 and spring 29 to shaft ,26 which Patent 7 2,975,782 jP-at'ent'ed :Mar..r21, .1951

F g C Crusher support member 14 has a pair of arms 30 and 31 in which shaft 32' is adjustably supported :by

angularly spaced screws 33 and 34. Axially spaced bearings 40 and 41 on shaft 32 support a sleeve 42 which, in turn, supports a pair of axially spaced dressing rollers 43 and 44, each having a curved portion for producing and maintaining a radius on the corners of a grinding wheel 13. The outer races of bearings 40 and 41 are located axially by means of spacer 45. The inner races of said bearings are held in spaced relation by a resilient device consisting of aspool-shaped member 50 positioned between a pair of cup-shaped members 53 and 54, each having --a rim portion engaging the adjacent flanges 51 and 52 ofspool-shaped member 50 at the outer portion thereon.

A small diameter portion 55 and 56 of each of said :cup-shaped members 53'and 54, engages the inner ring of each of bearings 40-annd 41. Bore 60 in shaft 32 'hasaplurality of radial outlets 61 through spool-shaped member 50. Bore 6t! also has a number of radial passages 65 extending through flange 66 on sleeve 42. Radial passages '65 extend to connect with outlet pasi sages67. Passages 67 are at such an angleto radial is rotatably mountedin suitable bearing members and 2s on bracket 17.

passages '65 that fluid being discharged therefrom at a high velocity, will cause rotation of dressing rollers 43 and 44. A mixture of air under pressure and lubricant is conducted into bore 60 from which it is distributed through radial outlets 61 to lubricate bearings 4t] and 41. Fluid also passes through radial passages 65 to eifect rotation of'dressingrollers 43 and 44 as described above. Thecurved portions of dressing rollers 43 and '44 are spaced a-distance greater than the space between the corners of the wheels which they are to form.

The crushing operation is performed by moving'dress ing rollers 43 and 44 axially into operative relation with the wheel corners. The means for effecting this axial 'm-ovement consists of a pair of L-shaped members 70 and 71in which the base portions are in over-lapping re- -lation.. Pivot member 75 extends through the over-lapping base portions ofsaid L-shaped members 70 and 71 through the back wall of bracket 17; The L-shaped members. 70 and 71 are held on pivot member 75 and are between spaced arms and 91.at one end of tilt block 92. The other end of tilt block 92 is slotted to extend on opposite sides of shaft 18 between collars and 101, each of which is rigidly attached to shaft 18.

.A three-cornered, constant diameter, cam is attachedto pivotshaft 111. Cam 110 is arranged to en- "gag'e the inside surfaces and 121 of L-shaped members 70 and 71 respectively. Rotation of cam 110 causes members 70 and 71 to rotate in opposite directions about "pivot member 75. The extent of such rotation of mem- "bers 70 and 7-1 is limited by stop pins 123 and 124. The positions of stop pins "123 and 124 may be adjusted by pointed'screw's 143 and 144 engaging similar points on stop'pins 123 and 124.

The upper end 950i tilt block 92 serves as a pivot relative to collars 100 and 101 so that pivot member "75 and bracket 17 are caused to move endwise on shaft 18 to shift dressing rollers 43 and 44 axially toalter- .nately engage the corners of grinding Wheel 13.

operation sothat a minimum time is required to move it into crushing position. This is accomplished by means of a pawl in engagement with teeth 1410f ratchet .sginent142; Ratchet segmeiit 142 is free to rotate on shaft 18 and is connected to bracket 17 by shaft 145 rigidly supported in side members 85 and 86 and fitting loosely in opening 147 in ratchet segment 142. The amount of movementof'shaft 145 ;in-opening 147 is determined by the' clearance between said shaft 145 and ;'said opening '147. ,The movement determines'the minimum extent of retraction of dressing rollers 43 and 44.

As grinding wheel 13 becomes smaller due to wearand dressing, ratchet segment 142 advances progressively with dressing rollers 43 and 44. However, when piston 162 and cylinder 161 are reversed, ratchet segment 142 remains in advance position and dressing rollers 43 and 44 may be retracted only the amount permitted by shaft 145 and ratchet segment 142 up to one full tooth. Shaft .145 is clamped by screws 150 and 151 in' collar 146 adjacent side members 85 and 86.

' Operation Cam 1'10 is a three-cornered uniform diameter type. Rotation of cam 110 causes members 70 and 71 and associated parts to oscillate as a unit. The center of oscillation is the end 95 of tilt block 92. This portion of block 92 is 'held stationary so that the oscillating movement is transmitted through pivot member 75 to bracket 17 to oscillate bracket 17 and dressing rollers 43 and 44. In the position of cam 110 shown in Fig. 1, dressing rollers 43 and 44 are in the neutral or intermediate position as shown in Fig. 3.

As cam 110 rotates in a counter-clockwise direction, members 70 and 71 and associated parts pivot about end 95 of block 92 in a counter-clockwise direction. Dressing roller 43 is moved to the right to dress the radius on the left hand corner of grinding wheel 13. As cam 110 continues to rotate in a counter-clockwise direction, members 70 and 71 and block 92 move in a clockwise direction and through pivot member 75, shifting bracket .17 to the left so that dressing roller 44 is moved to the contact LS2 to hold relay lCR.

Relay contact 1CR1 completes a circuit to energize valve solenoid 2, shifting valve 148 to the left, directing fluid under pressure to the left end of reversing valve 149, shifting valve 149 to the right.

In this position, valve 149 directs fluid under pressure to the right hand end of diamond traverse cylinder 152 to shift diamond traverse piston 153 to the left to traverse a diamond dressing tool (not shown) across the face of grinding wheel 13. When the diamond completes its movement to the left, limit switch 3LS is actuated. Limit switch contact 3LS1 opens, deenergizing relay 1CR and valve solenoid 2, permitting valve 148 to return to central position while diamond traverse piston 153 remains at the left hand position. Limit switch contact 3LS-2 is closed to complete a circuit through limit switch contact 4LS1 and normally closed relay contact 3CR1 to energize relay ZCR. Relay contact 2CR1 completes a circuit to energize valve solenoid 3, shifting dresser positioning valve 160 to the left and directing fluid under pressure to the upper end of dresser positioning cylinder 161.

Dressing rollers 43 and 44 move into engagement with grinding wheel 13. Crusher actuating piston 162 through arm 163 on piston rod 25, closes limit switch contact 5LS1 to complete a circuit to energize crusher traverse 4 relay 4CR. Relay contact 4CR1 completes a circuit to energize valve solenoid 4, shifting valve 170 to the left and directing fluid under pressure to the left end of roller traverse cylinder 130. Roller traverse piston 135 through link 133 rotates cam to cause dressing rollers 43 and 44 to engage first one corner of grinding wheel 13 and then the other.

At the end of the movement of roller traverse piston 135, limit switch contact 4LS1 is actuated by dog 136 on shaft 111 to deenergize relay 2CR and valve solenoid 3 so that dresser positioning valve 160 is returned to the right to direct fluid to the lower end of dresser positioning cylinder 161 to separate dressing rollers 43 and 44 from grinding wheel 13. This retracting movement of dressing rollers 43 and 44 opens limit switch contact 5LS1 and closes limit switch contact 5LS2. Opening limit switch contact 5LS1 deenergizes relay 4CR which, in turn, deenergizes valve solenoid 4.

The roller traverse valve 170 moves to the right to direct fluid to the right hand end of roller traverse cylinder to shift cylinder 130 to move roller traverse piston to the left and reverse cam 110 to return dressing rollers 43 and 44 to the intermediate position.

Limit switch contact 5LS2 completes a circuit to energize relay 5CR. Relay contact 5CR1 completes a circuit to energize valve solenoid 5, shifting valve 148 to the right and directing fluid under pressure to the left end of valve 149, shifting valve 149 to the right and directing fluid to the left end of cylinder 152, returning piston 153 and the diamond to the right to make a second pass of the diamond across the face of grinding wheel 13. This movement of the piston 153 actuates limit switch 3LS to deenergize relay 5CR to stop piston 153 in starting position.

I claim:

1. A dressing device for a grinding wheel'comprising a rotatable dressing member having formed corner dressing portions axially spaced from one another a distance greater than the spacing of the corners on the grinding wheel, a frame for rotatably supporting said dressing member, said frame being mounted for movement of said dressing member into and out of operative engagement with said grinding wheel, said dressing member being normally in intermediate position relative to said grinding wheel, means for effecting preliminary rotation of said dressing member to approximate the surface speed of said grinding wheel, means to effect engagement of said dressing member with said grinding wheel while said dressing member is in said intermediate position so as to synchronize the surface speed of said grinding wheel and said dressing member, and means for thereafter effecting a reciprocating movement of said dressing member to eflfect a dressing operation on one corner of said grinding wheel and then on the other corner of said grinding wheel.

2. A dressing device for a grinding wheel comprising a rotatable dressing member having formed corner dressing portions axially spaced from one another a distance greater than the spacing of the corners on the grinding wheel, a frame for rotatably supporting said dressing member, said frame being mounted for movement of said dressing member into and out of operative engagement with said grinding wheel, said dressing memher being normally in intermediate position relative to said grinding wheel, means for eifecting preliminary rotation of said dressing member to approximate the surface speed of said grinding wheel, means to effect engagement of said dressing member with said grinding wheel while said dressing member is in said intermediate position so as to synchronize the surface speed of said grinding wheel and said dressing member, means for thereafter effecting a reciprocating movement of said dressing member to effect a dressing operation on one corner of said grinding wheel and then on the other corner of said grinding wheel comprising a cam, means tween said cam and said dressing member wherebyro tation of said cam in one direction causes a reciprocating movement of said dressing member to engage one corner of said grinding wheel and then the other corner of said grinding wheel. 7

3. A dressing device for a grinding wheel comprising a rotatable dressing member having formed corner dressing portions axially spaced from one another a distance greater than the spacing of the corners on the grinding Wheel, a frame for rotatably supporting said dressing member, said frame being mounted for movement of said dressing member into and out of operative engagement with said grinding wheel, said dressing member being normally in intermediate position relative to said grinding wheel, means for eflecting preliminary rotation of said dressing member to approximate the surface speed of said grinding wheel, means to effect engagement of said dressing member with said grinding Wheel while said dressing member is in said intermediate position so as to synchronize the surface speed of said grinding Wheel and said dressing member, means for thereafter efiecting a reciprocating movement of said dressing member to effect a dressing operation on one corner of said grinding wheel and then on the other corner of said grinding wheel comprising a cam, means for ro tating said cam, connections between said cam and said dressing member whereby rotation of said cam'in one direction causes a reciprocating movement of said dressing member to engage one corner of said grinding wheel and then the other corner of said grinding wheel, and means for returning said 'cam to its original position and thereby returning said dressing member to said intermediate position.

4. A dressing device for a grinding wheel comprising a rotatable dressing member having formed corner dressing portions axially spaced from one another a distance greater than the spacing of the corners on a grinding wheel, a frame for rotatably supporting said dressing member, said frame being mounted for movement of said dressing member into and out of operative engagement with said grinding wheel, and means for efiecting an axial reciprocating movement of said frame and said dressing member comprising a piston and cylinder, one of which is attached to said frame, the other to a cam having a limited reciprocating movement.

5. A dressing device for a grinding wheel comprising a rotatable dressing member having formed corner dressing portions axially spaced from one another a distance greater than the spacing of the corners of a grinding wheel, a frame for rotatably supporting said dressing member, said frame being mounted for movement of said dressing member into and out of operative engagement with said grinding wheel, a ratchet movable With said frame, and a pawl for engaging said ratchet to limit the extent of withdrawal of said dressing member from said grinding wheel.

6. A dressing device for a grinding wheel comprising a rotatable dressing member having formed corner dressing portions axially spaced from one another a distance greater than the spacing of the corners of a grinding Wheel, a frame for rotatably supportingtsaid dressing member, said frame being mounted for movement of said dressing member into and out of engagement with said grinding wheel, a ratchet movable with said frame, a pawl for engaging said ratchet to limit the extent of Withdrawal of said dressing member from said grinding wheel so that as said grinding wheel becomes smaller due to wear, the extent of retraction of said dressing member will remain substantially constant.

7. A dressing device for a grinding wheel comprising a rotatable dressing member having formed corner dressing portions axially spaced from one another at a dis tance greater than the spacing of the corners on said grinding Wheel, means for rotatably supporting said dressing member for movement into and out of operative engagement with said grinding wheel, and means for effecting an axial reciprocating movement of said dressing member to dress first one and then the other corner of said grinding wheel.

No references cited. 

